寄主植物轮换饲养和次生代谢物交叉涂布对棉铃虫取食的影响

食物混合通常对多食性昆虫的生长表现有积极的影响,然而此前的研究对象主要是成虫期和幼虫期迁移能力较强的种类。某些鳞翅目种类尽管是多食性的,但其幼虫个体因时空隔离的原因,并无机会自由选择食料寄主。采用寄主叶片轮换饲养和次生代谢物交叉涂布两种方法研究了多食性棉铃虫幼虫的取食行为,供试寄主植物包括烟草、辣椒、番茄和棉花,次生代谢物采用自然浓度进行交叉涂布。结果表明,食物混合并没有造成幼虫总体摄食量的显著增加。其中,烟草和水合烟碱能显著抑制棉铃虫对其他寄主叶碟的取食,而辣椒及(E)-辣椒素对其他寄主叶碟的被食量均无影响。番茄叶片轮换饲养不影响棉铃虫对与其轮换的其他寄主叶片的被食量,但α-番茄苷涂布在辣椒和棉花叶碟上则对棉铃虫有显著拒食作用。棉花-烟草轮换饲养组中的烟草被食量显著大于烟草非轮换组中的烟草被食量,但(+)-棉酚涂布处理却能显著抑制棉铃虫对烟草的摄食。两种生物测定方法均未发现棉花与辣椒存在显著性相互影响。总之,棉铃虫可能是以耐受式的对策适应寄主植物次生代谢物的,符合相称性形态构成假说,即扩散能力较差的鳞翅目幼虫个体并不需要进化出同时应对来自两种或两种以上的寄主植物次生代谢物的适应机制。     

棉铃虫对几种信息化合物的触角电位 (EAG)反应

通过棉铃虫成虫对 1 0种寄主植物挥发性物质、两种性信息素组分及两者的混合作用的触角电位反应 ( EAG) ,发现棉铃虫雌雄蛾对 1 0种挥发性物质的 EAG反应差异显著 ( P<0 .0 5 ) ,说明了 1 0种挥发物质对棉铃虫成虫的感应功能有所不同。 1 0种寄主植物挥发物质与性信息素主要组分混合后能引起雄蛾 EAG反应明显高于单独性信息素的反应 ,其中有 4种挥发性物质明显地增强棉铃虫对性信息素的反应 ( P<0 .0 5 ) ,即庚醛、1 -己醇、反 - 2 -己烯醇、顺 - 3-己醇 - 1 ,说明了以寄主植物挥发物质与昆虫性信息素混合作用来增强昆虫性信息素的应用效果。不同光温条件下饲养的雄蛾对寄主植物挥发性物质与性信息素相互作用的 EAG反应差异显著 ( P<0 .0 5 )。     

棉铃虫对三氟氯氰菊酯的抗性狭义遗传力及其与体重的相关性

利用数量遗传学方法和半同胞交配设计,测定了棉铃虫Helicoverpa armigera对三氟氯氰菊酯抗性和体重的狭义遗传力,并分析了棉铃虫抗药性与其体重之间的相关性。结果表明,棉铃虫对三氟氯氰菊酯的抗性狭义遗传力为0.2476±0.0248,体重遗传力为0.3613 ± 0.1299;抗性与其母体效应无关;抗性与体重之间存在显著的遗传负相关。     

核型多角体病毒感染对棉铃虫幼虫同类相残行为的影响

在室内研究核型多角体病毒（HaSNPV）感染对棉铃虫Helicoverpa armigera（Htibner）幼虫同类相残行为的影响。结果显示：感病棉铃虫随感病程度的加重,越容易被健康棉铃虫残食,而自然死亡的感病棉铃虫、冻死的感病棉铃虫和冻死的健康棉铃虫三者被健康棉铃虫残食的百分率无显著差异。表明感病棉铃虫和病虫尸体更易于被健康棉铃虫残食,是由于棉铃虫体力减弱而失去反击能力,不是由于病毒本身的影响。以健康棉铃虫、感病棉铃虫为残食者,冻死的病虫为被残食者,相残率无显著差异,表明病毒并未改变棉铃虫残食同类的天性。残食病虫的健康棉铃虫的化蛹率和羽化率均低于正常的健康棉铃虫,残食者为相残行为付出了很高的代价。     

Effects of nuclear polyhedrosis virus on cannibalism in Helicoverpa armigera

在室内研究核型多角体病毒(HaSNPV)感染对棉铃虫Helicoverpa armigera(Hübner)幼虫同类相残行为的影响.结果显示:感病棉铃虫随感病程度的加重,越容易被健康棉铃虫残食,而自然死亡的感病棉铃虫、冻死的感病棉铃虫和冻死的健康棉铃虫三者被健康棉铃虫残食的百分率无显著差异.表明感病棉铃虫和病虫尸体更易于被健康棉铃虫残食,是由于棉铃虫体力减弱而失去反击能力,不是由于病毒本身的影响.以健康棉铃虫、感病棉铃虫为残食者,冻死的病虫为被残食者,相残率无显著差异,表明病毒并未改变棉铃虫残食同类的天性.残食病虫的健康棉铃虫的化蛹率和羽化率均低于正常的健康棉铃虫,残食者为相残行为付出了很高的代价.     

C3和C4植物寄主对华北地区棉铃虫越冬代和第一代的影响

确定华北越冬代棉铃虫虫源及其对第一代棉铃虫种群的影响是制定棉铃虫防治策略的基础。以越冬代棉铃虫蛾翅的稳定同位素δ¹³C为天然标记直接判定这些成虫的幼虫期寄主类型,并将雌虫接到春小麦植株上,调查其产卵、孵化、幼虫发育至化蛹、羽化等特征。结果表明,越冬代来自C₃植物(主要为棉花)的成虫个体数量占全部越冬羽化种群的53.1%,所产生的下一代老熟幼虫也较C₄来源的多(55.1%);雌蛾受精率都比较高;卵孵化率较高(52.9%>41.6%);幼虫发育在低龄阶段较比后者快,存活率低,但在高龄幼虫阶段相对后者慢,存活率高;与C₄植物(主要玉米)的来源个体后代的幼虫发育总历期接近,总存活率也相近。显示寄主植物小麦提供的营养条件在第一代棉铃虫的幼虫发育中具有决定性意义,即小麦只在特定阶段才适合幼虫的发育;而且不论是C₃还是C₄寄主来源的越冬代棉铃虫已经适应了这一限制。有效地评价了玉米和棉花等寄主植物对华北地区越冬代和次年第一代棉铃虫的影响,对于分析越冬代棉铃虫的虫源性质和第一代棉铃虫的防治及Bt抗性的治理有重要参考价值。     

华北棉区棉田中棉铃虫的取食行为及为害特征的研究

在大量田间实验的基础上,本文揭示华北棉区棉铃虫Heliothis armigera(Hbner)在棉田中的取食行为及其咬食棉花不同发育阶段的繁殖器官的组成和数量.根据棉铃虫的取食行为与其寄主植物棉花生长发育的关系,分别列出第二、三、四代幼虫期内棉花全株上各发育阶段的繁殖器官的组成、各龄幼虫所在果枝上繁殖器官的组成、各龄幼虫咬食不同发育阶段繁殖器官的组成和数量以及其中脱落的数量.分析了不同世代幼虫取食行为的差异,及其对棉花生长发育和产量形成过程的影响.建立了用于棉田害虫管理系统的棉铃虫取食模型.     

植物次生物质对烟青虫和棉铃虫食物利用及中肠解毒酶活性的影响

用分别添加0-5%(干重比)棉酚、烟碱、番茄苷和辣椒素4种植物次生物质的人工饲料饲养烟青虫Helicoverpa assulta和棉铃虫H. armigera 5龄幼虫48 h,测定这些次生物质对烟青虫和棉铃虫的营养效应和中肠谷胱甘肽S-转移酶（GST）及羧酸酯酶（CarE）活性的影响。结果表明：在实验浓度下,棉酚可显著降低烟青虫的相对消化率,但对棉铃虫却有助食作用;番茄苷抑制烟青虫的取食和生长,对其近似消化率和食物利用率也有显著的抑制作用,但食物转化率有明显升高,对棉铃虫的各营养指标无显著影响;烟碱对烟青虫和棉铃虫的相对生长率均无影响;辣椒素使烟青虫的取食量有大幅度的提高,对棉铃虫的取食量无影响,但引起其相对消化率的提高。由此可见,棉铃虫对4种次生物质有普遍的适应性,而烟青虫只对寄主植物所含的烟碱和辣椒素有较好的适应性。烟青虫和棉铃虫幼虫中肠CarE活性不受4种次生物质的影响,烟碱和辣椒素对烟青虫GST有显著的诱导作用,番茄苷对烟青虫GST活性则有抑制作用,4种次生物质对棉铃虫GST均无显著影响。     

用于昆虫嗅觉行为研究的四臂嗅觉仪的设计、制作和应用

昆虫在寻找奇主植物的过程中,寄主植物的气味传递着有关取食、产卵及其它活动的可行性信息,对昆虫的行为反应起着关键的作用~[1]。因此研究昆虫的嗅觉行为不仅能够揭示害虫与寄主植物间的化学联系,而且可为害虫的防治、预测预报提供新的思路与途径。笔者在参考国外文献的基础上,自行设计、制作了用于研究棉铃虫等飞翔活动能力较强的昆虫的四臂嗅觉仪。它兼具了国外文献介绍的嗅觉仪及风洞的特点,在研究棉铃虫对其寄主植物挥发性信息物质中取得了较好的结果,现将其结构、工作原理及初步的测试效果介绍如下。l基本结构及各部分的功能1．…     

棒花鱼形态特征的两性异形和雌性个体生育力

测定了棒花鱼(Abbottina rivularis)繁殖期形态特征包括体长、头长、头宽、头高、眼间距、鼻间距、背鳍基长、胸鳍长、胸鳍腹鳍间距、尾柄长、尾鳍长和体重的两性异形和雌性个体生育力。结果表明,雄性个体的数量显著多于雌性个体,雄性个体的体长显著大于雌性个体。特定体长的雌性个体的胸鳍腹鳍间距显著大于雄性个体,头长、头宽、头高、眼间距、鼻间距、背鳍基长、胸鳍长、尾柄长和尾鳍长显著小于雄性个体,雌雄两性体重不存在显著差异。棒花鱼的怀卵数量与体长和体重回归关系显著。偏相关分析显示,当控制第三者恒定时,怀卵数量与体长和体重呈正相关但不显著。棒花鱼存在个体大小和其他局部特征显著的两性异形,雌性个体主要通过腹腔容积的增加提高个体生育力。棒花鱼形态特征的两性异形是性选择和生育力选择共同作用的结果。     

棉铃虫在4个辣椒品种上的寄主适合度

在室内条件下,比较了棉铃虫幼虫对辣味程度依次下降的豫优鲜辣2号、豫艺绿冠、豫艺墨秀大椒和豫甜椒12号4个辣椒品种果实的嗜食性、食物转化率和利用率及种群增长情况。结果表明：（1）棉铃虫幼虫的取食选择性、对食物的近似消化率和利用率在4个辣椒品种之间存在明显差异。其中初孵、3龄和5龄幼虫对4个辣椒品种果实的选择性规律基本一致,在豫甜椒12号品种上幼虫出现的百分率和取食量比率均最大;随着辣椒品种辣味程度的降低,5龄幼虫在其上的取食时间和休息时间依次增加,活动时间则依次降低;取食4个辣椒品种的果实后,6龄幼虫的相对生长率、相对取食量和食物转化率差异不显著,但取食豫甜椒12号与豫优鲜辣2号和豫艺绿冠之间的近似消化率和食物利用率差异达显著水平。（2）室内271 ℃ 、70 %-80 % RH和16 L：8 D光周期条件下,棉铃虫在4个辣椒品种上均能完成其世代周期,随着辣椒品种辣味程度的增加,1龄幼虫和整个世代的发育历期依次延长,且在豫甜椒12号与豫优鲜辣2号之间差异达显著水平。其中在豫优鲜辣2号上棉铃虫的世代发育历期最长（27.86 d）,其次为豫艺绿冠（27.23 d）,再次为豫艺墨秀大椒（26.83 d）,在豫甜椒12号上的发育历期最短（25.85 d）;棉铃虫在4个辣椒品种上的世代存活率分别为豫优鲜辣2号为21.67%、豫艺绿冠为23.33%、豫艺墨秀大椒为23.33%、豫甜椒12号为35.00%;取食4个品种辣椒后,棉铃虫的蛹重差异不显著,其中雌蛹重分别为取食豫甜椒12号品种的为249.3 mg,取食豫艺墨秀大椒的为244.7 mg,取食豫艺绿冠的为243.4 mg,取食豫优鲜辣2号的雌蛹最轻,为209.4 mg。雄蛹重与雌蛹表现出的规律基本一致,但取食同一品种的雌蛹重均高于雄蛹重。（3）棉铃虫的种群净增殖率和内禀增长率在豫优鲜辣2号品种上最低,在豫甜椒12号品种上最高。以上结果表明,随着4个辣椒品种辣味程度的增加,棉铃虫在其上的寄主适合度则依次降低,其寄主适合度顺序为：豫甜椒12号＞豫艺墨秀大椒＞豫艺绿冠＞豫优鲜辣2号。     

转Bt棉花对蜘蛛生长发育及捕食行为的影响

室内评价了取食转Bt棉叶的棉铃虫幼虫对草间钻头蛛和八斑鞘腹蛛生长发育的影响.并通过捕食功能反应评价了取食了Bt棉叶的棉铃虫幼虫对成熟草间钻头蛛捕食行为的影响.室内饲养实验结果表明草间钻头蛛、八斑鞘腹蛛取食用转Bt棉叶处理的棉铃虫幼虫与取食普通棉叶处理的棉铃虫幼虫的发育历期、成蛛体重都没有显著差异.捕食功能反应实验结果表明草间钻头蛛对棉铃虫幼虫的捕食功能反应符合HollingⅡ型圆盘方程,两组不同猎物饲养成熟的草间钻头蛛对同种处理的棉铃虫幼虫的捕食行为没有显著差异.综合考虑：转Bt棉对蜘蛛生长发育、捕食能力没有显著的负作用.     

Bioinsecticidal activity of Murraya koenigii miraculin-like protein against Helicoverpa armigera and Spodoptera litura

Miraculin-like proteins, belonging to the Kunitz superfamily, are natural plant defense agents against pests and predators, and therefore are potential biopesticides for incorporation into pest-resistant crops. Here, a miraculin-like protein from Murraya koenigii was assessed for its in vitro and in vivo effects against two polyphagous lepidopteran insect pests, Helicoverpa armigera and Spodoptera litura. M. koenigii miraculin-like protein (MKMLP) inhibited the trypsin-like activity and total protease activity of H. armigera gut proteinases (HGP) by 78.5 and 40%, respectively, and S.litura gut proteinases (SGP) by 81 and 48%, respectively. The inhibitor was stable and actively inhibited the proteolysis of both HGP and SGP enzymes for up to 72 h. Incorporation of MKMLP into artificial diet adversely affected the growth and development of pests in a dose-dependent manner. After 10 days of feeding on diets containing 200 μM MKMLP, larval weight was reduced to 69 and 44.8% and larval mortality was increased to 40 and 43.3% for H. armigera and S litura, respectively. The LC(50) of MKMLP was 0.34 and 0.22% of the diet for H.armigera and S. litura, respectively. These results demonstrate the efficacy of MKMLP as a potential plant defense agent against H. armigera and S. litura.     

Is the common sowthistle (Sonchus oleraceus) a primary host plant of the cotton bollworm,Helicoverpa armigera (Lep., Noctuidae)? Oviposition and larval performance

Helicoverpa armigera (Hübner) is a polyphagous pest that has a relatively strong affinity in the field for the European weed Sonchus oleraceus L. in parts of Australia. The oviposition preference of H. armigera was examined in relation to sowthistle and some crop hosts on which it is a pest. In a group test with simultaneous exposure of moths to common sowthistle, maize, sorghum and two cotton cultivars, H. armigera females consistently showed strongest affinities for common sowthistle, irrespective of moth age or the original host of the test insects in the field. Females ( n  = 20) exposed individually to a choice between common sothistle and cotton, varied substantially in preference. Among the females tested, 67% showed a stronger affinity for common sowthistle, about 5% preferred cotton and 28% did not discriminate. Common sowthistle was also the most preferred by newly hatched larvae among the five host plant types presented in a multiple choice test. Larvae fed on common sowthistle flowers had a higher survival rate and body weight than those fed on cotton flowers. These results and previous field observations suggest that S. oleraceus may be a primary host plant (or one of the primary host species) to which H. armigera became adapted at the time of speciation.     

Computer simulation study on the cyclicities ofTribolium population dynamics

Under a set of assumptions, a mathematical model was constructed to investigate the effect of cannibalistic behavior and medium renewal schedule on Tribolium population dynamics, and the results of simulation analyses were presented to show how modelling can contribute to a better understanding of experimental study. The analyses of the present model, the main concern of which is the cyclicity in Tribolium population. showed that there are two distinct factors which create cyclicity, the cannibalistic behavior in Tribolium itself, and the medium renewal schedule. Cannibalism per se does not necessarily cause cyclicity, but the combinations of cannibalistic behavior among various life stages and their relative intensities among them can cause cyclicity and can also determine the period of cycle. External factors also can generate cyclicity, but their interaction with cannibalistic behavior has a more significant effect in modifying the period of cycle. Some discrepancies between the model and experimental results were discussed.     

Improvement of pest resistance in transgenic tobacco plants expressing dsRNA of an insect-associated gene EcR

The adoption of pest-resistant transgenic plants to reduce yield loss and pesticide utilization has been successful in the past three decades. Recently, transgenic plant expressing double-stranded RNA (dsRNA) targeting pest genes emerges as a promising strategy for improving pest resistance in crops. The steroid hormone, 20-hydroxyecdysone (20E), predominately controls insect molting via its nuclear receptor complex, EcR-USP. Here we report that pest resistance is improved in transgenic tobacco plants expressing dsRNA of EcR from the cotton bollworm, Helicoverpa armigera, a serious lepidopteran pest for a variety of crops. When H. armigera larvae were fed with the whole transgenic tobacco plants expressing EcR dsRNA, resistance to H. armigera was significantly improved in transgenic plants. Meanwhile, when H. armigera larvae were fed with leaves of transgenic tobacco plants expressing EcR dsRNA, its EcR mRNA level was dramatically decreased causing molting defects and larval lethality. In addition, the transgenic tobacco plants expressing H. armigera EcR dsRNA were also resistant to another lepidopteran pest, the beet armyworm, Spodoptera exigua, due to the high similarity in the nucleotide sequences of their EcR genes. This study provides additional evidence that transgenic plant expressing dsRNA targeting insect-associated genes is able to improve pest resistance.     

棉铃虫幼虫唾液腺cDNA文库的构建及EST分析

棉铃虫Helicoverpa armigera (Hübner)幼虫唾液中的各种酶类及各种生化组分在棉铃虫与植物相互作用及协同进化中起到重要作用; 唾液腺是棉铃虫唾液成分的合成器官。本研究通过构建棉铃虫幼虫唾液腺全长cDNA文库, 测序得到1 502条EST序列, 聚类分析后获得821个unigenes, 为筛选棉铃虫与寄主互作信号因子提供基因信息资源。使用Blast2 GO软件对821个unigenes进行了比对和功能注释, 初步获得棉铃虫幼虫唾液腺中mRNA的构成特征。结果显示, 在棉铃虫唾液腺ESTs文库中, 鉴定得到脂类相关消化酶基因17个, 糖类相关消化酶基因5个, 半胱氨酸蛋白酶基因1个, 丝氨酸蛋白酶基因20个（其中16个为新发现）, 提示唾液腺的主要功能是分泌消化酶进行预消化; 还发现在棉铃虫幼虫唾液腺中存在表皮蛋白、 气味结合蛋白和化学感受蛋白基因。结果为研究棉铃虫预消化系统打下基础。     

Cannibalistic behavior in red king crabs reared under artificial conditions

The cannibalistic behavior during all life history stages of the red king crab Paralithodes camtschaticus (Tilesius, 1815) raised under laboratory conditions was studied. All feeding stages were found to be cannibalistic. The major factors affecting the level of cannibalism were identified, and methods were proposed to reduce cannibalism intensity under laboratory conditions.     

光强度对棉铃虫交配行为的影响

【目的】为阐明光强度对棉铃虫Helicoverpa armigera (Hübner)交配行为的影响。【方法】本实验设置4个光照强度(0,0.5,5.0和50.0 lx),观察记录不同光照强度下棉铃虫雌蛾的求偶行为;分别通过单个腺体性信息素提取法和解剖雌虫受精囊的方式,检测不同光照强度下棉铃虫的雌蛾性信息素滴度和交配率。【结果】在强光(50.0 lx)下,棉铃虫雌蛾求偶起始时间最长,求偶持续时间最短,求偶次数最少,雌蛾性信息素滴度始终处于较低水平,交配率也属于最低。在微光(0.5 lx)下,雌蛾求偶起始时间最短,求偶持续时间最长,求偶次数最多;雌蛾性信息素始终处于较低水平,但暗期后段求偶率高达40%。【结论】强光(50.0 lx)可以抑制棉铃虫雌蛾的求偶行为、性信息素的合成及交配;微光(0.5 lx)可以促进棉铃虫雌蛾的求偶行为;相对黑暗环境(0 lx),微光(0.5 lx)还可以促进棉铃虫快速(1 h)完成交配,微光(0.5 lx)对棉铃虫的交配行为具有重要意义;求偶和性信息素的合成没有必然联系。本研究可为探讨光对夜蛾交配行为的影响提供一定的理论基础,也可为利用物理、化学通讯信息调控夜蛾行为提供一定的参考。     

Effect of temperature and photoperiod on juvenile hormone biosynthesis and sexual maturation in the cotton bollworm, Helicoverpa armigera: implications for life history traits

The Israeli population of the cotton bollworm, Helicoverpa armigera (Hübner), undergoes a short-day, low-temperature pupal diapause and is also suspected of being a seasonal migrant in the eastern Mediterranean region. H. armigera were reared in the laboratory under several constant temperature and photoperiodic combinations which simulate average conditions encountered in the spring, summer, early-autumn and late-autumn in Israel. Juvenile hormone (JH) biosynthesis, the onset of calling behavior, sex pheromone production and ovarian development were examined in virgin female moths subsequent to eclosion. Allatal maturation, defined as acquisition of competence to synthesize JH, was significantly delayed in moths reared under simulated spring conditions. This was probably the cause for the observed delay in ovarian development and the onset of calling behavior, and to the reduction in sex pheromone biosynthesis. The delay in female sexual maturation, commonly associated with migratory flight, is consistent with presumptive pre-reproductive migration in H. armigera.